You need to add the rights to set the revision to the state(s) you are interested in. In the revision number tab of this state(s), the variable used to manage the index must be configured.
Once done, when you click on "Set Revision" a window of the type get version appears. Right-click the line of the file(s) and select Set all new revision values to the card variable value.
Otherwise there is also in the pc starter an import flow that allows you to recognize the revision, as long as the files have the same profile as those already in PDM